Water drains typically clog due to materials becoming lodged in the traps, joints or other locations. Typically, a clog can be freed by applying pressure on the upper extent of the drain. There are a multitude of devices available for applying pressure yet they are all deficient in one manner or another.
Devices commonly referred to as “plungers” comprise a force cup with a handle attached thereto. The force cup is brought into contact with the drain entrance and pushed down by the handle thereby forcing water to contact the clog with pressure. A force cup device typically does not have a sufficient volume to apply enough pressure on the clog to be effective. Exemplary force cup devices are disclosed in U.S. Pat. Nos. 1,706,315; Des. 364,251 and Des. 292,631. The low pressure exerted by force cup devices has led to the development of other types of devices.
Piston devices comprising a piston slidably received within a cylinder are an improvement over force cup devices. The piston devices typically comprise a fixed tube with a piston that transits therein to apply pressure at the exit end of the tube. Examples include U.S. Pat. Nos. 1,684,880; 3,934,280; 4,186,451; 5,199,114; 5,522,094 and 5,940,897. These devices are often adequate for unclogging drains yet they require many parts and multiple seals thereby increasing the cost of manufacture and the susceptibility of failure. Each piston must have a seal between the piston and the outer tube to be effective. The piston must also be sealed to the push rod. Furthermore, the upper end of the tube must have a leak to allow air to enter above the piston to avoid a pressure decrease above the piston which would work against the downward force. These devices, while functional, have yet to receive widespread acceptance over the plunger.
A telescoping tube drain opening device is disclosed in U.S. Pat. No. 4,096,597. The telescoping tube drain opening device utilizes water as a pressure source and has an internal membrane incorporated in the upper tube. This device has several deficiencies. The use of water to dislodge the elements clogging a drain causes additional problems. First, it is not uncommon for the sink, or toilet, to be close to fill when the effort to dislodge the clog is initiated. If a water source is used the additional water may cause the sink, or toilet, to overflow which is highly undesirable. It is not uncommon for the unclogging operation to have to be repeated which further exasperates the problem of adding additional water to the clogged appliance. If water from the clogged device is used the spoiled water is drawn into the telescoping tubes which causes problems such as trapped bacteria and other oderiferous material. The flap valve is also a point of deficiency. If water is carried from a separate source the flap valve is prone to leaking. Furthermore, after the water is discharged the flap valve will no longer be under pressure and will therefore seal with some amount of spoiled water trapped therein.
There has been a long felt desire in the art for a device suitable for unclogging drains which is economical, efficient and sanitary.